Shell ejecting mechanism for machine guns



March 2, 1948. F. x. RATAICZAK SHELL EJECTING MECHANISM FOR MACHINE GNSFiled May 2.3, 1945 2 sheets-sheet 1 E N 9 f. 1 A t n. om .1 \v^ n m 9vo wm um v 4 Qi fnv 4 March 2, 1948.

Y1.-. l. RATAICZAKi SHELL EJECTING MECHANISM FOR MAHINE GUNS Filed May25;"1945 2 sheets-sheet 2 `INVENTOR.

Patented Mar. 2, 1948 SHELL EJECTING MECHANISM FOR MACHINE GUNS FrancisI. Rataczak, Dayton,

General Motors Corporation, Dayton, corporation of Delaware Ohio,assignorl to h10, a

Application May 23, 1945, Serial No. 595,265

(Cl. l12-25) 10 onim's.

This invention relates to ordnance and more particularly to an improvedshell ejecting mechanism for use in a machine gun.

The invention set forth herein represents an improvement over themechanism set forth in my co-pending applications Serial Nos. 536,229and 565,252 filed May 19, 1944 and November 27, 1944, respectively, Thelatter application has matlired into Patent No. 2,411,979 of December 3,

It is an object of this invention to provide a rugged shell ejectingmechanism capable of electing empty shells from a high speed machine gunwithout damaging or breaking away fragments of the rims of the shells.

Another object of this invention is to provide an improved shellejecting mechanism which is inexpensive and trouble-free.

Another object of this invention is to provide an improved arrangementfor supporting the shell ejecting mechanism relative to the rest of thegun parts. Y Y

Still another object of this invention is to provide an improved shellej ecting mechanism which can be used in existing guns without makingany major changes in the gun construction which has otherwise proven tobel Very satisfactory.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 is a fragmentary view, partly in section, showing the arrangementof my improved shell ejecting mechanism relative to the rest of the gunparts;

Fig. 2 is a fragmentary View, with parts broken away, showing a shellbeing ejected by my improved shell ejecting mechanism; i

Fig. 3 is a fragmentary elevational view yof the shell ejector and thefeedway which has been superimposed upon a diagrammatic showing of thereceiver and the receiver housing;

Fig. 4 is a fragmentary sectional view taken substantially on line 4-4of Fig. 5 showing the relationship of the shell ejectingmechanisrnrelative to the feedway and the cover;

Fig. 5 is a top view showing the relationship of the shell ejectingmechanism to the conventional feedway; and

Fig, 6 is a fragmentary view on an enlarged scale showing therelationship of the shell to the shell ejecting cam when the shell firstengages the `cam.

Referring now to the drawings, reference numorals III, I2 and I4designate the receiver housing, the cover, andthe gun barrel,respectively. As set forth more fully in my co-pending applications, theshells are fed into the gun on a feedway I6 which is hel-din placebetween the receiver I9 and the cover I2. The bolt mechanism comprises amain portion I5 and a bolt head I'I both of which are mounted forreciprocation within the receiver I0 in accordancewith present practice.The bolt head I'I is provided 'with a conventional type of extractor I8which serves to extract the empty shells from the barrel I4 as the boltand bolt head move to the rear upon recoil. As best shown in Fig. 2, theempty shell 20 strikes against a shell ejecting cam 22 which is carriedby and actually formed as an integral part of the mounting bar 24 asshown in Figs. 3, 4 and 5. The shell ejecting cam 22 is yieldablymounted so as to provide for movement of the cam relative to the bolthead, the cover and the rest of the gun elements. The ejected shellsleave through the ejection opening 21 in the bottom of the receiver I9.

As best shown in Figs. 3 and 5, the mounting lbar 24 is loosely oradjustably supported by means of studs 25 rigidly carried by the endwall 28 of the conventional feedway i6. The mounting har 24 is providedwith elongated slots 30 through which the studs 25 project so as toguide and limit the movement of the mounting bar 24. The relationship ofthe mounting bar 24, the shell ejecting cam 22 and the feedway I6 isshown in Fig, 5 wherein a portion of the'end wall 29 which is directlyabove the cam 22, has been broken away to facilitate illustration. Asbest shown in Figs. 4 and 5, holes 34 have been drilled into the frontface of the mounting bar 24 for the reception of spring means 3B asshown. The springs 36 serve to bias the mounting bar24 away from therear wall 28 of the feedway I5. Referring now to Fig. 4, it will beobserved that the cover` I2 is provided with a cam surface 38 whichcooperates with a complementary vcam surface @Il formed on the mountingbar 24. Each side ange of the cover l2 is provided with such a camsurface. The cam surfaces 38 and 49 are made parallel to the cam surface29 on the forward end of the ejecting cam 22 and are directly in linewith the cam surface 29 so that any force applied to the cam surface 29by the empty shell striking the surface 25 is transmitted directly tothe cover I2 through the surfaces 38.

As shown in Fig. 4, the cover I2 is cut away at III and 42 so as toprovide clearance between the mounting bar 24 and the edges of the coverat these places. 'I'he pressure of the springs 36 against the bar 24tends to cause the mounting bar 24 to move downwardly by virtue of theinclined cam surfaces 38 and 40 described hereinabove. 'Ihe surfaces 38and 40 are normally in sliding engagement at all times although there isrelative movement between the bar 24 and the cover I2. The spring 36helps to keep the surfaces 38 and 40 in contact with one another at alltimes. The arrangement of the springs 3B and the surfaces 38 and 40 issuch that the bar 24 is biased downwardly by the springs 36. However, asthev bolt head reciprocates within the receiver housing I the cam 22together with the mounting bar 24 is free to move upwardly out of thepath of the bolt head. 'Ihe lower .position of the ejector has beenshown in dot-dash lines in Fig, 4 of the drawing. By virtue of thisarrangement, the exact relationship of the cover relative to the path ofthe bolt is not as critical as in the prior shell ejector design shownin my co-pending application Serial No. 565,252, which has matured intoPatent No. 2,411,979 of December 3, 1946. Furthermore, a slightlydifferent form of action takes place in that the cover I2 which limitsthe movement of the mounting bar 24 is at all times in engagement withthe mounting bar 24 through the surfaces 38 and 4U in such a manner thatthe coverdoes not receive a hammer blow from the mounting bar 24 whenthe shell strikes the cam surface 26, The studs 25 are providedwithremovable heads or stops 44 which hold the mounting bar 24 in assembledrelationship relative to the end wall 28. The arrangement describedhereinabove serves as a convenient self-compensating means capable ofcompensating for inaccuracies in the .manufacture of the gun andsubsequent wear which tends to alter the clearances between the parts ofthe gun.

While the form of embodiment of the invention as herein .disclosed.constitutes a preferred form, it is to be understood that other formsmight be adopted, as may come within the `scope of the claims whichfollow.

What is claimed is as follows:

1. In a rapid fire machine gun having a receiver, a receiver cover,shell ejecting mechanism comprising a mounting bar extendingtransversely of the receiver between the cover and the receiver, a shellengaging cam depending from said bar and arranged so as to engage theupper rear edge of .each empty shell upon extraction of the shell fromthe gun barrel, and means for adjustably mounting said bar, said bar andsaid receiver cover having complementary cam surfaces in slidingengagement with one another and arranged at an angle relative to thehorizontal axis of the gun, said cam surfaces being so arrangedWherebyrearward movement of said bar will cause downward movement ofsaid bar, and spring means urging said .surfaces into engagement withone another.

2. In a rapid fire machine gun having a receiver housing, a cover forthe receiver housing, and a reciprocating bolt mechanism disposed Withinsaid receiver housing; a shell ejecting mechanism .comprising a shellengaging cam and mounting means for yieldably supporting said shellengaging cam between said cover and said receiver housing, said shellengaging cam comprising' a cam element disposed directly above and insliding engagement with said reciprocating .bolt so as to be movedupwardly by said bolt 4 as said bolt moves past said element and havinga forward end for engagement with the chamfer on the rim of the emptyshell, said cover and said mounting means having complementary camsurfaces in engagement with one another and slidable relative to oneanother, said surfaces being arranged so that the shell eje'ctingmechanism is cammed forwardly as it moves upwardly.

3. In a rapid fire machine gun, a receiver housing, a cover for saidreceiver housing, a reciprocating bolt mechanism disposed within saidreceiver housing, a shell feedway disposed between said cover and saidreceiver housing, a shell electing mechanism carried by said feed- Wayand including a depending member having a cam surface for engaging theupper edge of the empty shells upon extraction of the shells, a portionof said depending member being arranged to project into the path ofmovement of said reciprocating bolt mechanism so as to be raised by saidbolt mechanism, vsaid cover and said shell ejecting mechanism havingcontacting cam surfaces arranged at an angle to the path of movement ofsaid bolt mechanism, and spring means biasing said contacting camsurfaces into engagement with one another.

4. In a rapid fire machine gun, a receiver housing, a cover for saidreceiver housing, a reciprocating bolt mechanism disposed within saidreceiver housing, a shell feedway disposed between said cover and saidreceiver housing, a shell ejecting mechanism carried by said feedway andincluding a depending fmember having a cam surface for engaging theupper edge of the empty shells upon extraction of the shells, a portionof said depending member being arranged to project into the lpath ofmovement of said reciprocating bolt mechanism so as to be raised by saidbolt mechanism, said cover and said shell ejecting mechanism havingcontacting cam surfaces arranged at an angle to the path of movement ofsaid bolt mechanism, and spring means biasing said contacting camsurfaces into engagement with one another, the arrangement 0f said camsufaces relative to said spring means being such that said spring meansbiases the shell ejecting mechanism downwardly relative to said cover.

5. Inl a rapid fire machine gun having a receiver, a receiver cover, anda feedway mounted between the receiver and the receiver cover, a shellejecting mechanism comprising a mounting bar loosely carried by saidfeedway and extending transversely of the receiver between the cover andthe receiver, a shell engaging element depending from said bar andarranged so as to engage the upper rear edge of each empty shell uponextraction of the shell from the gun barrel, spring means interposedbetween said feedway and said mounting bar biasing said mounting bartowards the rear of the gun, said cover having cam means arranged inengagement with a portion of said mounting bar for camming said mountingbar downwardly as the mounting bar moves to the rear, said cam means,mounting bar, and feedway being so constructed and arranged thatrearward movement of said mounting bar causes said downward movement.

6. In a rapid re machine gun, a receiver housing, a barrel, a cover forsaid receiver housing, a reciprocating bolt mechanism disposed Withinsaid receiver housing, said receiver housing having an ejection openingin the bottom wall thereof, a shell ejecting mechanism comprising ashell electing cam disposed above the path o f movement of said bolt forengagement with the empty shells upon extraction from said barrel andfor interrupting backward movement of the upper edge of the shell so asto ilip the shell downwardly through said opening, means for biasingsaid shell ejecting mechanism rearwardly of the gun, and cam means forcamming the shell ejecting mechanism {downwardly as the shell ejectingmechanism moves rearwardly.

7. In a firearm, the combination with a receiver housing; of a shellelecting mechanism comprising a mounting bar loosely carried by saidreceiver housing, a shell ejecting cam element depending from saidmounting bar and having a forward inclined surface for engagement withthe rim of an empty shell in the process of extraction, means forbiasing said mounting bar towards the rear, and cam means for cammingsaid mounting bar downwardly as the mounting bar moves towards therear', said cam means having a cam surface substantially parallel tosaid inclined surface.

8. In a firearm, the combination with a stationary receiver housingpart; of a shell ejecting mechanism comprising a shell ejecting element,a mounting bar extending transversely of said housing for supportingsaid element in the path of movement of the edge portion of the emptyshells being extracted from the barrel of the gun, means for looselymounting said bar on said housing part, said last named means being soconstructed and arranged that the mounting bar is free to move bothvertically and horizontally, and means for guiding the movement of saidmounting bar so as to move at an angle relative to the vertical and thehorizontal.

' 9. In a rapid re machine gun, a receiver housing, a barrel, a coverfor said receiver housing, a reciprocating bolt mechanism disposedWithin said receiver housing, said receiver housing having an ejectionopening in the bottom wall thereof, a shell ejecting mechanismcomprising a shell ejecting cam disposed above the path of movement ofsaid bolt for engagement with the empty shells upon extraction from saidbarrel and for interrupting backward movement `of the upper edge of theshell so as to ip the shell downwardly through said opening, a mountingbar for said shell ejecting cam arranged transversely of said receiverhousing with the ends of the bar projecting on opposite sides of saidhousing, means for loosely supporting the projecting ends of said bar,said cover having an inclined surface provided thereon, said mountingbar having a complementary inclined surface arranged in sliding contactwith said rst named inclined surface, and spring means for biasing saidsurfaces into mutual engagement, said spring means and said surfacesbeing so constructed and arranged that said shell ejecting cam isnormally biased downwardly into shell ejecting position but is allowedto move upwardly enough so as to allow passage thereunder of saidreciprocating bolt mechanism.

10. In a rapid re machine gun, a receiver housing, a reciprocating boltmechanism disposed within said receiver housing, a shell ejectingmechanism carried by said housing and including a depending memberhaving a cam surface for engaging the upper edge of the empty shellsupon extraction of the shells, a portion of said depending member beingarranged to project into the path of movement of said reciprocating boltmechanism so as to be raised by said bolt mechanism, said housing andsaid shell ejecting mechanism having contacting cam surfaces arranged atan angle to the path of movement of said bolt mechanism, and springmeans biasing said contacting cam surfac into en' gagement with oneanother, the arrangement of said cam surfaces relative to said springmeans being such that said spring means bias said shell ejectingmechanism downwardly relative to said housing.

FRANCIS I. RATAICZAK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 580,935 Ehbets Apr. 20, 1897828,977 Schouboe Aug. 21, 1906 1,041,410 Benet et al, Oct. 15, 19121,090,351 Swebilius Mar. 17, 1914 1,786,207 Hudson Dec. 23, 19302,101,236 Burton Dec. 7, 1937

